This invention relates generally to improved operation of power doors on mass transit vehicles, and more particularly the detection of door malfunctions during vehicular operation either due to linkage failure or obstruction in the path of a closing door, in either case, conditions under which train movement should be inhibited.
The system and apparatus disclosed utilizes panel sensing through actuation by the moving panel of a fixed location sensor, providing an indication of door panel passage past predetermined points along the door travel path.
Panel sensing has been disclosed in U.S. Pat. No. 3,857,197, assigned to the same assignee as the instant application, said patent is herein incorporated by reference. The apparatus disclosed and claimed in U.S. Pat. No. 3,857,197 works well and is in use, however, the system does not adequately provide for detection of "small" obstructions in the path of a properly operating power door. Further, the switch actuating mechanism as disclosed does not incorporate certain features required to provide a door system capable of detecting "small" obstructions on closing the doors of a vehicle so equipped.
Applicants' discovery as disclosed herein includes improvements upon the panel sensing system described in U.S. Pat. No. 3,857,197 which essentially overcome the above mentioned difficulties in transit vehicle operation and door control.
Accordingly, it is an object of this invention to provide a power door system for use in a mass transit vehicle having a panel sensing/obstruction detection function which allows determination of improper door operation either due to malfunction of the door actuator linkage, or an obstruction in the path of vehicular door on closing.
It is an additional object of this invention to provide a door closure system including obstruction detection on door closure which allows removal of an obstruction preventing door closing without an undue increase in passenger discharge times of a given vehicle.
It is a further object of this invention to provide a power door closure system including a means for detecting malfunctioning or damaged door closure equipment, thereby preventing movement of a train having improperly operating doors.
It is yet an additional object of this invention to minimize passenger loading and unloading times through the use of a novel door panel sensing mechanism which provides an indication of car door system malfunction.